In conjunction with any application pursuant to Section 66-21 (Determination and Certification for Transit Volumes), 66-31 (Determination and Certification for Optional Transit Volumes) and 66-51 (Additional Floor Area for Mass Transit Station Improvements), modifications may be granted pursuant to Section 66-521 (Authorization for transit-adjacent sites or qualifying transit improvement sites) or Section 66-522 (Special permit for transit-adjacent sites or qualifying transit improvement sites).